WO2006043350A1

WO2006043350A1 - Process for producing stacked ceramic electronic component and composite laminate

Info

Publication number: WO2006043350A1
Application number: PCT/JP2005/009132
Authority: WO
Inventors: Ryuichiro Wada; Tetsuya Ikeda
Original assignee: Murata Manufacturing Co., Ltd.
Priority date: 2004-10-18
Filing date: 2005-05-19
Publication date: 2006-04-27
Also published as: JP4375402B2; CN101040354B; CN101040354A; US20070180684A1; JPWO2006043350A1; US7607216B2

Abstract

This invention provides a stacked ceramic electronic component which can solve a problem that, when a stacked ceramic electronic component with a built-in inductor element, such as a multilayer ceramic substrate, is produced, the incorporation of an unsintered core to be provided in the inductor element causes diffusion of a material and does not sometimes provide inherent properties. In a composite laminate (56) which provides a contemplated multilayer ceramic substrate upon firing, a core (68) formed of a magnetic ceramic sinter is incorporated. In order to reduce the difference in shrinkage behavior during firing between this core (68) and an unsintered ceramic layer (57a to 63a), shrinkage suppression layers (71 and 72)containing an inorganic material powder which is not substantially sintered at the sintering temperature of the unsintered ceramic layer (57a to 63a) is provided in a composite laminate (56).

Description

Specification

Multilayer ceramic electronic component manufacturing method and composite laminate

Technical field

TECHNICAL FIELD [0001] The present invention relates to a method for producing a multilayer ceramic electronic component incorporating a coiled conductor, and a composite laminate prepared for producing such a multilayer ceramic electronic component. .

Background art

[0002] As multilayer ceramic electronic components that are of interest to the present invention, as described in, for example, JP-A-11-260642 (Patent Document 1) and JP-A-2000-150239 (Patent Document 2), Some have built-in inductor elements. In these Patent Documents 1 and 2, in order to manufacture a multilayer ceramic electronic component with a built-in inductor element, an unsintered core composed mainly of an unsintered magnetic material and a non-sintered core are required. A coiled conductor made of an unsintered conductive paste film formed around the core and an unsintered outer layer mainly composed of an unsintered nonmagnetic material surrounding the unsintered core and coiled conductor A method comprising the steps of first producing an unsintered laminated body comprising a portion and firing the entire unsintered laminated body simultaneously is described.

However, in the above-described firing step provided for the manufacturing method of the multilayer ceramic electronic component described in Patent Documents 1 and 2 described above, different materials are fired at the same time. The material contained in the conductive paste film that becomes a conductor (for example, Ag) Force may diffuse into the S core, or the material contained in the unsintered core (eg, Fe, Ni, etc.) may diffuse into the outer layer is there. As described above, when the diffusion of the material progresses between the core, the coiled conductor, and the outer layer portion, it becomes difficult to obtain the original characteristics of each, and for example, desired characteristics as an inductor element can be obtained. May not be obtained for type ceramic electronic components.

Patent Document 1: Japanese Patent Laid-Open No. 11-260642

Patent Document 2: JP 2000-150239 A

Disclosure of the invention Problems to be solved by the invention

Accordingly, an object of the present invention is to provide a method for manufacturing a multilayer ceramic electronic component that can solve the above-described problems.

[0005] Another object of the present invention is to provide a composite laminate prepared for producing the above-described multilayer ceramic electronic component.

Means for solving the problem

The present invention is first directed to a method for manufacturing a multilayer ceramic electronic component incorporating an inductor element. The manufacturing method of the multilayer ceramic electronic component according to the present invention is characterized by having the following configuration in order to solve the technical problem described above.

That is, the method for manufacturing a multilayer ceramic electronic component according to the present invention includes a core made of a magnetic ceramic sintered body, a coiled conductor formed around the core, and a core and a coiled conductor between the layers. At least two unsintered ceramic layers that are stacked with the sandwiched between them and a specific unsintered ceramic layer, and is not sintered at the sintering temperature of the unsintered ceramic layer. It comprises a step of producing a composite laminate comprising a shrinkage suppression layer containing an inorganic material powder, and a step of firing the composite laminate at a temperature at which the unsintered ceramic layer sinters.

[0008] The step of producing the composite laminate described above includes a step of preparing a core, a step of preparing a plurality of ceramic green sheets to be an unsintered ceramic layer, and a first of the first ceramic Darin sheet. Forming a first conductor pattern to be a part of a coiled conductor on the main surface of the second ceramic sheet and a second part to be the other part of the coiled conductor on the first main surface of the second ceramic green sheet. The first main surface of the first ceramic clean sheet and the first main surface of the second ceramic green sheet face each other with the core interposed, and the first The first ceramic green sheet and the second ceramic green sheet are overlapped so that the end of the conductor pattern and the end of the second conductor pattern are in contact with each other to form a conductor extending in a coil shape. It is preferable to provide a step of bringing.

[0009] In the above-described preferred embodiment, the step of superimposing the first ceramic green sheet and the second ceramic green sheet includes a first conductor pattern on the first main surface of the first ceramic green sheet. After placing the core so that the end of the It is preferable that the second ceramic green sheet is superposed on the first ceramic green sheet.

[0010] Further, in this preferred embodiment, the step of producing the composite laminate includes the steps of forming the second main surface and the second ceramic green sheet facing the first main surface of the first ceramic green sheet. It is preferable that the method further includes a step of forming a shrinkage suppression layer on each of the second main surfaces facing the first main surface.

[0011] Further, in this preferred embodiment, each of the first and second conductor patterns preferably includes a plurality of strip-shaped conductor portions, whereby the number of turns of the coil-shaped conductor is preferably plural. .

[0012] In the method for manufacturing a multilayer ceramic electronic component according to the present invention, the core may have any shape such as a flat plate shape, a cylindrical shape, an elliptical column shape, or a donut shape.

[0013] The shrinkage suppression layer can be disposed at any location of the composite laminate. When the shrinkage suppression layer is disposed so as to form the outermost layer of the composite laminate, it is preferable to further include a step of removing the shrinkage suppression layer after the firing step. When the shrinkage suppression layer is disposed along a specific interface between the unsintered ceramic layers, the shrinkage suppression layer is solidified by infiltration of a part of the material contained in the unsintered ceramic layer in the firing process. It is preferable to be done. Even in this case, the shrinkage suppression layer may be further arranged so as to form the outermost layer of the composite laminate as described above.

[0014] The composite laminate is a first shield having a magnetic ceramic sintered body force arranged along an interface between specific unsintered ceramic layers so as to sandwich the core and the coiled conductor in the lamination direction. It is preferable to further provide a plate. In this case, the composite laminate has a second magnetic ceramic sintered body force that is disposed so as to sandwich the core and the coil conductor at the interface between the unsintered ceramic layers where the core and the coiled conductor are located. It is more preferable to further provide the shield plate.

[0015] The multilayer ceramic electronic component manufactured by the manufacturing method according to the present invention is a multilayer ceramic electronic component having a plurality of combined functions including an inductor function, even if it is a single function element providing an inductor function. It may be a substrate. In the former case, the unsintered ceramic layer is It is preferred that the main component is a low-temperature sintered ceramic material or a magnetic material. In the latter case, the unsintered ceramic layer is mainly composed of a low-temperature sintered ceramic material. It is preferable.

The present invention is also directed to a composite multilayer body prepared for manufacturing a multilayer ceramic electronic component incorporating an inductor element.

[0017] The composite laminate according to the present invention was laminated with a core having a magnetic ceramic sintered body strength, a coiled conductor formed around the core, and a core and the coiled conductor sandwiched between layers. At least two unsintered ceramic layers, and a shrinkage suppression layer including an inorganic material powder disposed so as to be in contact with a particular unsintered ceramic layer and not substantially sintered at the sintering temperature of the unsintered ceramic layer; It is characterized by having. Through the step of firing the composite laminate, a multilayer ceramic electronic component is manufactured.

[0018] In the composite laminate according to the present invention, the coiled conductors are respectively formed on the mutually opposing main surfaces of the first and second unsintered ceramic layers sandwiching the core and the coiled conductor. Preferably, the first and second conductive patterns are provided. These first and second conductor patterns are in a state where their respective end portions are in contact with each other so as to form a conductor extending in a coil shape.

The invention's effect

[0019] According to the present invention, the composite laminate to be fired includes a core made of a magnetic ceramic sintered body. Therefore, in the firing step, the core, the coiled conductor, and the unsintered ceramic layer There is virtually no diffusion of material between each of these. As a result, it is possible to maintain the original material characteristics possessed by the core that also has the strength of a magnetic ceramic sintered body. Therefore, in the obtained multilayer ceramic electronic component, the inductor element configured with the core and the coiled conductor can give the characteristics as designed.

[0020] In addition, the composite laminate includes a core having a sintered body strength and an unsintered ceramic layer. In the firing step, the unsintered ceramic layer tends to shrink relatively large. Due to the difference in shrinkage from the unsintered ceramic layer, a relatively large internal stress is generated in the composite laminate, which may cause warping, undulation, or cracking after firing. Conceivable. However, in this invention, the composite laminate is an unsintered ceramic layer. Is provided with a shrinkage suppression layer for suppressing the shrinkage of the green ceramic layer so that the shrinkage in the principal surface direction of the unsintered ceramic layer does not substantially occur. Cracks occur, and multilayer ceramic electronic components can be manufactured with high yield.

[0021] Further, according to the present invention, in the composite laminate, since the non-sintered ceramic layer and the shrinkage suppression layer other than the core are in an unsintered state, the composite laminate without forming the cavity in advance. The core can be built in. This eliminates the need for relatively complicated processes for forming the cavity and inserting the core into the cavity.

Therefore, a low cost due to the simplification of the process can be expected.

[0022] Further, according to the present invention, the magnetic permeability of the core incorporated in the composite laminate can be arbitrarily selected. Therefore, the inductance can be controlled not only by changing the number of turns of the coiled conductor but also by changing the magnetic permeability, and the inductance given by the inductor element can be controlled over a wide range.

[0023] Further, according to the present invention, cores having different magnetic permeability can be built in the same plane in the multilayer ceramic electronic component. For this reason, it is not necessary to form wiring conductors for connecting between the coil-shaped conductors provided in relation to each core between a plurality of ceramic layers, so that the load imposed on the wiring conductors can be reduced and safety can be reduced. The specified characteristics can be ensured, so that it can be applied to large current applications such as power supplies, and the multilayer ceramic electronic components can be made low-profile.

[0024] In the present invention, in order to produce a composite laminate, a step of forming a first conductor pattern to be a part of a coiled conductor on the first main surface of the first ceramic green sheet; Forming a second conductor pattern as the other part of the coiled conductor on the first main surface of the ceramic green sheet of 2 and the first main surface of the first ceramic green sheet with the core interposed And the first main surface of the second ceramic green sheet face each other, and the end of the first conductor pattern and the end of the second conductor pattern are in contact with each other to form a conductor extending in a coil shape If the first ceramic green sheet and the second ceramic green sheet are overlapped with each other so as to be in a state of being provided, a via-hole conductor is provided on a specific ceramic green sheet. Child forming a conductor extending in a coil shape Nag and You can. Therefore, a process requiring a relatively high cost for providing the via-hole conductor is not required, and the manufacturing cost of the multilayer ceramic electronic component can be reduced.

[0025] When the composite laminate is manufactured as described above, the coiled conductor formed around the core can be formed in close contact with the core. For this reason, the generated magnetic flux can be completely confined, and the inflection point of the magnetic field can be suppressed. Therefore, a low-loss inductor element can be realized.

In the above-described embodiment, when each of the first and second conductor patterns includes a plurality of strip-shaped conductor portions, the number of turns of the coil-shaped conductor can be easily increased. At this time, the arrangement pitch of the plurality of strip-shaped conductor portions can be narrowed without being restricted by the dimensions required for the via-hole conductor. When this band-shaped conductor part force S is formed by screen printing, the arrangement pitch of the band-shaped conductor parts depends only on the printability of screen printing, so the pitch should be narrowed to 30 / zm, for example. Can do. As a result, it is possible to reduce the size of the coil-like conductor and, consequently, the size of the multilayer ceramic electronic component.

[0027] In the case of producing a composite laminate according to the above-described embodiment, the process power for superposing the first ceramic green sheet and the second ceramic green sheet is the first of the first ceramic green sheet. After arranging the core so that the end of the first conductor pattern is exposed on the main surface of the first ceramic sheet, the second ceramic green sheet is overlaid on the first ceramic green sheet while interposing the core When implemented, a composite laminate can be made by stacking each element provided there from one end side in the stacking direction, making it possible to produce a composite laminate without applying complicated processes. can do

[0028] In the present invention, the composite laminate is disposed along the interface between specific unsintered ceramic layers so as to sandwich the core and the coiled conductor in the lamination direction. If the first shield plate is further provided, in the firing step, in addition to the shrinkage suppression effect of the shrinkage suppression layer, the shrinkage suppression effect of the first shield plate can be exhibited. In addition, the inductor element force composed of a core and a coiled conductor can confine magnetic lines of force that develop in the stacking direction, so that it is placed around it. For example, it is possible to shield elements that are easily affected by a magnetic field, such as a transformer, and to reduce loss.

[0029] In the above-described case, the magnetic composite ceramic is disposed so as to sandwich the core and the coiled conductor at the interface between the unsintered ceramic layers where the core and the coiled conductor are located. If the second shield plate having a sintered body strength is further provided, the confinement state of the magnetic field lines becomes more complete, and the loss of the inductor element can be further reduced.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing an inductor element 1 as a first example of a multilayer ceramic electronic component manufactured by applying the manufacturing method according to the present invention.

[FIG. 2] FIG. 2 shows a first ceramic green sheet 8 prepared for manufacturing the inductor element 1 shown in FIG. 1, wherein (a) is a plan view and (b) Is a cross-sectional view along line B-B in (a).

[FIG. 3] FIG. 3 shows a state in which the core 2 is arranged on the first ceramic green sheet 8 shown in FIG. 2, (a) is a plan view, and (b) is a view of (a). It is sectional drawing which follows line BB.

[FIG. 4] FIG. 4 shows a second ceramic green sheet 16 prepared for manufacturing the inductor element 1 shown in FIG. 1, wherein (a) is a plan view and (b) FIG. 4 is a sectional view taken along line BB in (a).

[FIG. 5] FIG. 5 shows a composite laminate 24 obtained by superimposing the structure shown in FIG. 3 and the structure shown in FIG. 4. (a) is a plan view. (b) is a sectional view taken along line BB in (a).

FIG. 6 is a cross-sectional view showing an inductor element 27 as a second example of the multilayer ceramic electronic component manufactured by applying the manufacturing method according to the present invention.

FIG. 7 is a cross-sectional view showing an inductor element 28 as a third example of a multilayer ceramic electronic component manufactured by applying the manufacturing method according to the present invention.

FIG. 8 is a perspective view showing a core 2a used in place of the core 2 provided in each of the inductor elements 1, 27 and 28 shown in FIGS. 1, 6 and 7, respectively.

FIG. 9 is a perspective view showing a core 2b used in place of the core 2 provided in each of the inductor elements 1, 27 and 28 shown in FIGS. 1, 6 and 7, respectively. [FIG. 10] FIG. 10 shows a first example prepared for producing the composite multilayer body 37 shown in FIG. 13 prepared for obtaining an inductor element as a fourth example of a multilayer ceramic electronic component. FIG. 3 shows a ceramic green sheet 38, which corresponds to FIG. 2 (a).

FIG. 11 is a view corresponding to FIG. 3 (a), showing a state where the core 46 is arranged on the ceramic green sheet 38 shown in FIG. 10.

FIG. 12 is a view corresponding to FIG. 4 (a), showing a second ceramic green sheet 47 prepared for producing the composite laminate 37 shown in FIG. 13.

FIG. 13 is a view corresponding to FIG. 5 (a), showing a composite laminate 37 obtained by superimposing the structure shown in FIG. 11 and the structure shown in FIG. 12. .

14 is a cross-sectional view showing ceramic green sheets 57b to 63b and shrinkage suppression green sheets 71b and 72b prepared for producing the composite laminate 56 shown in FIG. 15 separately from each other.

FIG. 15 is a cross-sectional view showing a composite laminate 56 obtained by laminating ceramic green sheets 57b to 63b and shrinkage suppression green sheets 71b and 72b shown in FIG.

FIG. 16 is a cross-sectional view showing a multilayer ceramic substrate 55 obtained by firing the composite laminate 56 shown in FIG.

FIG. 17 is a cross-sectional view showing a state in which surface-mounted components 75 to 77 are mounted on multilayer ceramic substrate 55 shown in FIG.

FIG. 18 is a cross-sectional view showing a composite laminate 78 produced to obtain a multilayer ceramic substrate as a sixth example of the multilayer ceramic electronic component.

FIG. 19 is a cross-sectional view showing a multilayer ceramic substrate 80 as a seventh example of the multilayer ceramic electronic component.

Explanation of symbols

1, 27, 28, 70 Inductor element

2, 2a, 2b, 46, 68 cores

3, 53, 69 Coiled conductor

4, 5, 29, 30, 57-63 Ceramic layer 8, 16 Ceramic green sheet or green ceramic layer

9, 17, 39, 48 First main surface

10, 40, 73 First conductor pattern

11, 19, 41, 50 Strip conductor

14, 20, 44, 51 Second main surface

15, 21, 45, 52, 71, 72, 79 Shrinkage inhibiting layer

18, 49, 74 Second conductor pattern

24, 37, 56, 78 Composite laminate

31 ~ 34, 81 ~ 84 Shield plate

55, 80 multilayer ceramic substrate

57a ~ 63a Unsintered ceramic layer

57b ~ 63b ceramic green sheet

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIG. 1, an inductor element 1 includes a core 2 having a magnetic ceramic sintered body force such as a plate-like ferrite, a coiled conductor 3 formed around the core 2, and a core between layers. 2 and two ceramic layers 4 and 5 laminated with a coiled conductor 3 sandwiched therebetween. Such an inductor element 1 is manufactured by the manufacturing method described with reference to FIGS.

In each of FIGS. 2 to 5, (a) shows a plan view, and (b) shows a sectional view taken along line BB in (a).

First, as shown in FIG. 2, a first ceramic green sheet 8 to be the ceramic layer 4 is prepared. The first ceramic green sheet 8 is preferably composed mainly of a low-temperature sintered ceramic material, for example, a slurry obtained by dispersing a mixed powder consisting of alumina powder and borosilicate glass powder in an organic vehicle. It is produced by forming a sheet into a sheet by the casting method.

[0036] The first ceramic green sheet 8 is mainly made of the low-temperature sintered ceramic material as described above. In addition to the component, it may be composed mainly of a magnetic material such as ferrite.

[0037] On the first main surface 9 of the first ceramic green sheet 8, the first conductor pattern 10 which is a part of the coiled conductor 3 described above is formed. The first conductor pattern 10 is formed by screen printing a conductive paste. The first conductor pattern 10 includes a plurality of strip-like conductor portions 11 that are parallel to each other! The number of the strip-like conductor portions 11 is selected in consideration of a desired inductance. Further, the line Z space of the strip-shaped conductor portion 11 is also selected in the range of 30 to 2000 μm in consideration of a desired inductance.

[0038] The first conductor pattern 10 also has input / output end portions 12 and 13 connected to the strip-shaped conductor portion 11 located at the end portion. The input / output end portions 12 and 13 are formed so as to reach the edge of the first ceramic green sheet 8.

In addition, a shrinkage suppression layer 15 is formed on the second main surface 14 facing the first main surface 9 of the first ceramic green sheet 8. The shrinkage suppression layer 15 includes an inorganic material powder such as alumina powder that does not substantially sinter at the sintering temperature of the first ceramic green sheet 8, and includes, for example, alumina powder in an organic vehicle. It is formed from a slurry obtained by dispersing.

[0040] The shrinkage suppression layer 15 is formed by stacking a green sheet obtained by forming the above-mentioned slurry into a sheet shape by a casting method on the second main surface 14 of the first ceramic green sheet 8. Alternatively, the slurry may be formed by applying the slurry onto the second main surface 14 of the second ceramic green sheet 8.

Further, as shown in FIG. 3, a flat core 2 having a thickness of, for example, 50 to 300 m is prepared. As described above, the core 2 is composed of, for example, a magnetic ceramic sintered body such as ferrite, and the firing temperature for obtaining this is higher than the firing temperature of the composite laminate described later. Favored ,.

Next, as shown in FIG. 3, the core 2 is disposed on the first main surface 9 of the first ceramic green sheet 8. At this time, the core 2 is aligned so that the end portions of the first conductor pattern 10, more specifically, the end portions of each of the plurality of strip-like conductor portions 11 are exposed. Core 2 At this stage, it is preferable that the first ceramic green sheet 8 is temporarily fixed with an adhesive or the like so that no positional deviation occurs.

On the other hand, as shown in FIG. 4, a second ceramic green sheet 16 is prepared. The second ceramic green sheet 16 is to be the ceramic layer 5 shown in FIG. 1, and on the first main surface (the surface facing downward in FIG. 4) 17, other than the coiled conductor 3. A second conductor pattern 18 is formed. The second conductor pattern 18 includes a plurality of strip-shaped conductor portions 19 that are parallel to each other.

In addition, a shrinkage suppression layer 21 is formed on the second main surface 20 facing the first main surface 17 of the second ceramic green sheet 16.

[0045] For the materials and forming methods of the second ceramic green sheet 16, the second conductor pattern 18 and the shrinkage suppression layer 21 described above, the first ceramic green sheet 8 and the first conductor described above are used. This is substantially the same as in the case of the pattern 10 and the shrinkage suppression layer 15.

Next, as shown in FIG. 5, the structure shown in FIG. 3 and the structure shown in FIG. 4 are overlapped. More specifically, with the core 2 interposed, the first main surface 9 of the first ceramic green sheet 8 and the first main surface 17 of the second ceramic green sheet 16 face each other, and the first The first ceramic green sheet 8 and the second ceramic so that the end of the second conductor pattern 10 and the end of the second conductor pattern 18 are in contact with each other to form a coil-shaped conductor. Green sheet 16 is overlaid. At this time, each end portion of the plurality of strip-shaped conductor portions 11 included in the first conductor pattern 10 is in contact with each end portion of the corresponding strip-shaped conductor portion 19 included in the second conductor pattern 18, and A coil-like conductor having a number of turns is formed.

[0047] As described above, a composite laminate 24 as shown in Fig. 5 is obtained. In the composite laminate 24, the first and second ceramic green sheets 8 and 16 described above form first and second unsintered ceramic layers, respectively. Accordingly, in the following description, the reference numerals “8” and “16” indicating the first and second ceramic green sheets are used to indicate the first and second unsintered ceramic layers, respectively. Will also be used.

[0048] The composite laminate 24 is laminated with the core 2 having magnetic ceramic sintered body strength, the coiled conductor 3 formed around the core 2, and the coil 2 and the coiled conductor 3 sandwiched between the layers. The first and second unsintered ceramic layers 8 and 16 and the shrinkage suppression layers 15 and 21 disposed so as to be in contact with the unsintered ceramic layers 8 and 16, respectively.

[0049] Next, after the composite laminate 24 is pressed in the laminating direction, it is fired at a temperature and a predetermined atmosphere at which the unsintered ceramic layers 8 and 16 are sintered. Next, when the shrinkage suppression layers 15 and 21 are removed, an inductor element 1 as shown in FIG. 1 is obtained.

[0050] In the firing step described above, the core 2 has a sintered body force, and therefore, diffusion of material between the core 2 and the coiled conductor 3 and each of the unsintered ceramic layers 8 and 16 occurs. Virtually does not occur. Therefore, the original material characteristics of the magnetic ceramic sintered body possessed by the core 2 can be maintained.

[0051] Further, in the firing step, the shrinkage suppression layers 15 and 21 act so as to suppress the shrinkage of the unsintered ceramic layers 8 and 16, and thus the obtained inductor element 1 is warped, swelled or cracked. The inductor element 1 can be manufactured with a very high yield.

[0052] Further, since the shrinkage suppression layers 15 and 21 forming the outermost layer are not sintered in the above-described firing step, they can be easily removed. The shrinkage suppression layers 15 and 21 are formed relatively thin, and in the firing step, a part of the material contained in the unsintered ceramic layers 8 and 16 is permeated into the shrinkage suppression layers 15 and 21, and the shrinkage suppression layer 15 And 21 may be solidified. In this case, the shrinkage suppression layers 15 and 21 are left in the inductor element 1 as a product. Further, the shrinkage suppression layer may be formed along the interface between each of the unsintered ceramic layers 8 and 16 and the coiled conductor 13, for example. In addition, only one of the shrinkage suppression layers 15 and 21 forming the outermost layer may be formed.

Although not shown in FIGS. 1 to 5, external terminal electrodes electrically connected to the input / output end portions 12 and 13 of the coil conductor 3 are provided on the outer surface of the inductor element 1. It is formed.

FIGS. 6 and 7 show inductor elements 27 and 28 as second and third examples of multilayer ceramic electronic components manufactured by applying the manufacturing method according to the present invention, respectively. FIG. Corresponds to the elements shown in Figure 1 in Figures 6 and 7. The same reference numerals are given to the elements to be repeated, and the duplicate description is omitted.

Inductor elements 27 and 28 shown in FIGS. 6 and 7, respectively, further include ceramic layers 29 and 30 in addition to ceramic layers 4 and 5 as ceramic layers.

[0056] In the inductor element 27 shown in FIG. 6, the shield plates 31 and 32 having the magnetic ceramic sintered body force so as to sandwich the core 2 and the coil conductor 3 in the laminating direction are provided with ceramic layers 4 and 29, respectively. And the interface between the ceramic layers 5 and 30.

On the other hand, in the inductor element 28 shown in FIG. 7, at the interface between the ceramic layers 4 and 5 where the core 2 and the coiled conductor 3 are located, the core 2 and Shield plates 33 and 34 having magnetic ceramic sintered body strength are arranged so as to sandwich the coiled conductor 3.

[0058] The composite laminate produced to manufacture such inductor elements 27 and 28 includes a green ceramic layer that should be ceramic layers 4, 5, 29, and 30, and has a magnetic ceramic layer. The shield plates 31 to 34 having a sintered body strength are arranged along the interface between these unsintered ceramic layers.

[0059] As described above, the composite laminates manufactured to manufacture the inductor elements 27 and 28, respectively, do not have the shield plates 31 and 32 that have a relatively large and large magnetic ceramic sintered body strength. Since it is disposed along a specific interface between the sintered ceramic layers, in the sintering process, in addition to the shrinkage suppression effect by the shrinkage suppression layer, the shrinkage suppression effect by the shield plates 31 and 32 can be exhibited.

Further, according to the inductor element 27 shown in FIG. 6, the loss can be reduced by the effect of confinement of the magnetic lines of force by the shield plates 31 and 32. In the inductor element 28 shown in FIG. 7, the effect of confining the magnetic lines of force by the shield plates 33 and 34 can be further exhibited, so that the loss can be further reduced.

Note that the inductor element 27 shown in FIG. 6 may be modified so as to include only one of the shield plates 31 and 32. In addition, the inductor element 28 shown in FIG. 7 may be changed so as to have only one of the shield plates 31 to 34. FIG. 8 and FIG. 9 are perspective views showing alternative examples of the core 2 provided in each of the inductor elements 1, 27 and 28 described above.

[0063] In each of the inductor elements 1, 27, and 28, as shown in the figure, a flat core 2 was used. Such a core 2 has the advantage that the shrinkage behavior can be easily matched with the unsintered ceramic layers 8 and 16 in a firing process in which a thinner one is preferred!

[0064] On the other hand, the core 2a shown in FIG. 8 has a cylindrical shape with a circular cross section. Use of such a core 2a has an advantage that the loss in the coiled conductor 3 can be reduced because there is no concentration of magnetic flux.

[0065] The core 2b shown in FIG. 9 has an elliptic cylinder shape with an elliptical cross section. According to such a core 2b, the same effect as in the case of the core 2a described above can be expected, and the handling property is better than that of the cylindrical core 2a. It can be expected that the shrinkage behavior can be easily matched with the other.

FIG. 10 to FIG. 13 are diagrams sequentially showing the manufacturing process of the composite laminate 37 produced to obtain the inductor element as the fourth example of the multilayer ceramic electronic component of interest to the present invention. FIGS. 10, 11, 12, and 13 are plan views corresponding to FIGS. 2 (a), 3 (a), 4 (a), and 5 (a), respectively.

[0067] Hereinafter, a method for producing the composite laminate 37 will be described. As far as the manufacturing method of the composite laminate 37 is concerned, a method substantially similar to the manufacturing method of the composite laminate 24 described with reference to FIGS. 2 to 5 described above can be applied unless otherwise specified. .

First, as shown in FIG. 10, a first ceramic green sheet 38 to be a ceramic layer is prepared. On the first main surface 39 of the first ceramic green sheet 38, a first conductor pattern 40 that is a part of a coiled conductor is formed. The first conductor pattern 40 includes a plurality of strip-like conductor portions 41 arranged in an arc shape. The first conductor pattern 40 includes input / output end portions 42 and 43. The input / output end portions 42 and 43 are formed so as to reach the edge of the first ceramic green sheet 38.

In addition, a shrinkage suppression layer 45 is formed on a second main surface (a surface facing downward in FIG. 10) 44 that faces the first main surface 39 of the first ceramic green sheet 38. . In Figure 10, The shrinkage suppression layer 45 is in a position hidden under the first ceramic green sheet 38.

On the other hand, as shown in FIG. 11, a donut-shaped core 46 is prepared. The core 46 also has a magnetic ceramic sintered body force such as ferrite. The cross-sectional shape of the core 46 may be rectangular, or other shapes such as a circle and an ellipse.

Next, as shown in FIG. 11, the core 46 force is disposed on the first main surface 39 of the first ceramic green sheet 38. At this time, the core 46 is aligned so that the end portions of the first conductor pattern 40, more specifically, the end portions of the plurality of strip-like conductor portions 41 are exposed.

On the other hand, as shown in FIG. 12, a second ceramic green sheet 47 to be a ceramic layer is prepared. On the first main surface (surface facing downward in FIG. 12) 48 of the second ceramic green sheet 47, a second conductor pattern 49 serving as the other part of the coiled conductor is formed. The second conductor pattern 49 includes a plurality of strip-like conductor portions 50 arranged in an arc shape.

In addition, a shrinkage suppression layer 52 is formed on a second main surface (a surface facing upward in FIG. 12) 51 facing the first main surface 48 of the second ceramic green sheet 47. . In FIG. 12, the second ceramic green sheet 47 is in a position hidden under the shrinkage suppression layer 52.

Next, as shown in FIG. 13, the structure shown in FIG. 11 and the structure shown in FIG. 12 are overlapped. More specifically, with the core 46 interposed, the first main surface 39 of the first ceramic green sheet 38 and the first main surface 48 of the second ceramic green sheet 47 face each other and the first The first ceramic green sheet 38 and the second ceramic so that the end of the conductor pattern 40 and the end of the second conductor pattern 49 are in contact with each other to form a conductor extending in a coil shape. Green sheet 47 is overlaid.

At this time, each end of the plurality of strip-shaped conductor portions 41 provided in the first conductor pattern 40 is in contact with each end of the corresponding strip-shaped conductor portion 50 provided in the second conductor pattern 49. A coiled conductor 53 constituting a coil-shaped conductor having a plurality of turns is formed so as to extend along the donut-shaped core 46 as a whole.

[0076] About the composite laminate 37 thus obtained, as in the case of the above-described embodiment, the pressing step, the firing step, the removal step of the shrinkage suppression layers 45 and 52, and the external terminal electrode A forming step is performed, whereby the target inductor element is obtained.

[0077] While the present invention has been described with respect to a method for manufacturing an inductor element as a single-function element having an inductor function, the present invention is a multilayer ceramic substrate having a plurality of functions including an inductor function. This method can also be applied. Hereinafter, an embodiment when the present invention is applied to a method for manufacturing a multilayer ceramic substrate will be described.

14 to 16 are cross-sectional views for explaining a method for manufacturing a multilayer ceramic substrate 55 as a fifth example of the multilayer ceramic electronic component.

Describing schematically, in order to obtain the multilayer ceramic substrate 55 shown in FIG. 16, the composite laminate 56 shown in FIG. 15 is produced. The composite laminate 56 is disassembled into elements as shown in FIG. 14 in the stage before lamination. In the method for manufacturing the multilayer ceramic substrate 55, the above-described manufacturing method for the inductor element 1 and the like can be basically applied unless otherwise specified.

First, the configuration of the multilayer ceramic substrate 55 will be described with reference to FIG.

The multilayer ceramic substrate 55 includes a plurality of ceramic layers 57 to 63. Further, the multilayer ceramic substrate 55 serves as a wiring conductor along a specific interface between each of several external conductor films 64 and 65 formed on one and the other main surfaces thereof and ceramic layers 57 to 63, respectively. And several via-conductors 66 provided so as to penetrate through a specific one of the ceramic layers 57 to 63. These wiring conductors constitute a passive element such as a capacitor or an inductor by at least a part thereof.

In addition, the multilayer ceramic substrate 55 includes an inductor element 70 including a flat core 68 and a coil conductor 69 formed around the core 68. Inductor element 70 is disposed between ceramic layers 60 and 61. The inductor element 70 has substantially the same structure as the inductor element 1 or the like as a single function element described above.

A composite laminate 56 produced for producing the multilayer ceramic substrate 55 as described above will be described with reference to FIG. 14 and FIG. 14 and FIG. 15, elements corresponding to those shown in FIG. 16 are denoted by the same reference numerals, and redundant description is omitted. [0084] As shown in FIG. 15 and FIG. 16, the composite laminate 56 shown in FIG. 15 includes unsintered ceramic layers 57a to 63a corresponding to the ceramic layers 57 to 63, respectively. I have. In relation to each of these unsintered ceramic layers 57a to 63a, outer conductor films 64 and 65, an inner conductor film 66 and a via-hole conductor 67 are provided. Between the unsintered ceramic layers 60a and 61a, an inductor element 70 including a core 68 and a coiled conductor 69 is disposed. Further, shrinkage suppression layers 71 and 72 are disposed so as to form the outermost layer of the composite laminate 56.

In order to produce the composite laminate 56 as shown in FIG. 15, ceramic green sheets 57b to 63b respectively corresponding to the unsintered ceramic layers 57a to 63a are prepared as shown in FIG. Shrinkage suppression green sheets 7 lb and 72b corresponding to the shrinkage suppression layers 71 and 72, respectively, are prepared. Further, a flat core 68 having magnetic ceramic sintered body strength is prepared.

[0086] Next, a specific one of the ceramic green sheets 57b to 63b is provided with a via-hole conductor 67. Further, the inner conductor film 66 is formed on each upper main surface of the ceramic green sheets 57b to 60b positioned below the core 68, and the ceramic green sheets 61b to 63b positioned above the core 68. Are formed on each lower main surface. Note that at least a part of the inner conductor film 66 formed on the upper main surface of the ceramic green sheet 60b may be formed on the lower main surface of the ceramic green sheet 61b.

An external conductor film 64 is formed on the upper main surface of the shrinkage suppression green sheet 71b, and an external conductor film 65 is formed on the lower main surface of the shrinkage suppression green sheet 72b. These outer conductor films 64 and 65 are forces that are transferred to the ceramic green sheets 57b and 63b, respectively, in the subsequent process. The reason for forming the green sheets 71b and 72b is to avoid the complexity of forming the ceramic film 57b and 63b in such a manner that the conductor films are aligned with each other on both main surfaces.

[0088] Further, a first conductor pattern 73 that is a part of the coil-shaped conductor 69 is formed on the upper main surface of the ceramic green sheet 60b, and a coil is formed on the lower main surface of the ceramic green sheet 61b. A second conductor pattern 74 which is the other part of the shaped conductor 69 is formed. These first and The second conductor patterns 73 and 74 have substantially the same shape as the first and second conductor patterns 10 and 18 shown in FIGS.

Next, in order to obtain the composite laminate 56 shown in FIG. 15, a lamination process is performed as follows.

Referring to FIG. 14, first, ceramic green sheets 57b-60b are sequentially laminated on shrinkage-suppressing green sheet 71b, and the obtained laminate is pressed in the laminating direction at a pressure of 20-150 MPa, for example. The

[0091] Next, the core 68 is disposed on the ceramic green sheet 60b. At this time, the core 68 is aligned so that the end portion of the first conductor pattern 73 is exposed. The core 68 is temporarily fixed to the ceramic green sheet 60b with an adhesive or the like.

On the other hand, ceramic green sheets 63b to 61b are sequentially laminated on the shrinkage-suppressing green sheet 72b, and the obtained laminated body is pressed in the lamination direction at a pressure of 20 to 150 MPa, for example.

[0093] Next, a stack body including a shrinkage suppression green sheet 71b, ceramic green sheets 57b to 60b, and a core 68, and a shrinkage suppression green sheet 72b and ceramic green so that the ceramic green sheets 60b and 61b described above face each other. Laminates with sheets 6 lb to 63b are stacked and the whole is pressed in the laminating direction, for example at a pressure of 20 to 200 MPa.

In this manner, the composite laminate 56 shown in FIG. 15 is obtained.

[0095] Next, a firing step is performed in which the composite laminate 56 is fired at a temperature and a predetermined atmosphere at which the unsintered ceramic layers 57a to 63a are sintered. Then, after firing, the shrinkage suppression layers 71 and 72 are removed, whereby the multilayer ceramic substrate 55 shown in FIG. 16 is obtained. In the firing step, if a pressure of about 50 to about LOOOkPa is applied to the composite laminate 56 in the stacking direction, a multilayer ceramic substrate 55 with better flatness can be obtained. Next, the outer conductor films 64 and 65 are plated as necessary.

FIG. 17 shows a state in which the surface mount components 75 to 77 are mounted on the multilayer ceramic substrate 55 shown in FIG. The surface-mounted components 75 to 77 are surface-mounted on the multilayer ceramic substrate 55 by being electrically connected to the external conductor film 65 by soldering or the like. FIG. 18 is a cross-sectional view showing a composite laminate 78 produced to obtain a multilayer ceramic substrate as a sixth example of the multilayer ceramic electronic component. The composite laminate 78 shown in FIG. 18 has many elements in common with the composite laminate 56 shown in FIG. 15. Therefore, in FIG. 18, the elements corresponding to the elements shown in FIG. The same reference numerals are assigned, and duplicate descriptions are omitted.

The composite laminate 78 shown in FIG. 18 is characterized in that a shrinkage suppression layer 79 is disposed along the interface between the unsintered ceramic layers 57a to 63a. As a result of the firing process in which the shrinkage suppression layer 79 is relatively thin, a part of the material contained in the unsintered ceramic layers 57a to 63a penetrates and is solidified. Therefore, the shrinkage suppression layer 79 does not need to be removed later.

[0099] In the embodiment shown in FIG. 18, the shrinkage suppression layer 79 is disposed along all interfaces, the force S disposed along all interfaces between the unsintered ceramic layers 57a-63a. You don't have to.

[0100] Further, in the composite laminate 78 shown in FIG. 18, a shrinkage suppression layer that forms outermost layers such as the shrinkage suppression layers 71 and 72 shown in FIG. 15 may be further formed.

FIG. 19 is a cross-sectional view showing a multilayer ceramic substrate 80 as a seventh example of the multilayer ceramic electronic component manufactured by applying the manufacturing method according to the present invention. Since the multilayer ceramic substrate 80 shown in FIG. 19 includes many elements in common with the multilayer ceramic substrate 55 shown in FIG. 16, the elements corresponding to the elements shown in FIG. The same reference numerals are attached, and duplicate descriptions are omitted.

A multilayer ceramic substrate 80 shown in FIG. 19 is characterized by having a configuration substantially the same as that of the inductor element 28 shown in FIG.

That is, the magnetic ceramic sintering strength is also increased along the interface between the ceramic layers 59 and 60 and the interface between the ceramic layers 61 and 62 so that the core 68 and the coiled conductor 69 are sandwiched in the stacking direction. The first shield plates 81 and 82 are disposed, and the core 68 and the coiled conductor 69 are sandwiched between the core 68 and the coiled conductor 69 at the interface between the ceramic layers 60 and 61. Two shield plates 83 and 84 are arranged. [0104] These shield plates 81 to 84 perform substantially the same functions as the shield plates 31 to 34 shown in FIG.

[0105] In this embodiment, the composite laminate produced to obtain the multilayer ceramic substrate 80 has shield plates 81 to 84 formed of unsintered ceramic layers as in the case of the inductor element 28 shown in FIG. It has a structure arranged at a specific interface.

[0106] Although the present invention has been described with reference to the illustrated embodiment, various modifications can be made within the scope of the present invention.

For example, the coiled conductor provided in association with the core can be variously modified with respect to its form and the like. Further, the form of the wiring conductor in the multilayer ceramic substrate can be variously changed as necessary.

[0108] Further, the arrangement of the inductor elements in the multilayer ceramic substrate can be variously changed, and two or more inductor elements may be incorporated in one multilayer ceramic substrate. In this case, even if the inductor elements are arranged along the interface between different ceramic layers in the multilayer ceramic substrate, they should be arranged along the interface between the same ceramic layers.

Claims

The scope of the claims

[1] A method for producing a multilayer ceramic electronic component incorporating an inductor element, comprising: a core having a magnetic ceramic sintered body strength; a coiled conductor formed around the core; At least two unsintered ceramic layers laminated with a coiled conductor sandwiched between them and the specific sintering temperature of the unsintered ceramic layer are arranged so as to be in contact with the unsintered ceramic layer. A step of producing a composite laminate comprising a shrinkage suppression layer containing an inorganic material powder that is not thermally sintered,

And firing the composite laminate at a temperature at which the unsintered ceramic layer sinters.

[2] The step of producing the composite laminate includes:

Preparing the core;

Preparing a plurality of ceramic green sheets to be the green ceramic layer;

Forming a first conductor pattern to be a part of the coiled conductor on the first main surface of the first ceramic green sheet;

Forming a second conductor pattern which is the other part of the coiled conductor on the first main surface of the second ceramic green sheet;

With the core interposed, the first main surface of the first ceramic green sheet and the first main surface of the second ceramic green sheet face each other, and an end of the first conductor pattern And a step of superimposing the first ceramic green sheet and the second ceramic green sheet such that the end of the second conductor pattern is in contact with each other to form a conductor extending in a coil shape When

The method for producing a multilayer ceramic electronic component according to claim 1, further comprising:

[3] The step of superimposing the first ceramic green sheet and the second ceramic green sheet includes the step of forming the first conductor pattern on the first main surface of the first ceramic green sheet. Arranging the core so that the end portion is exposed; and superimposing the second ceramic green sheet on the first ceramic green sheet with the core interposed therebetween. The multilayer ceramic electronic component according to claim 2. Production method.

[4] The step of producing the composite laminate includes a second main surface opposite to the first main surface of the first ceramic green sheet and the first main surface of the second ceramic green sheet. 3. The method for manufacturing a multilayer ceramic electronic component according to claim 2, further comprising a step of forming the shrinkage suppression layer on each of the second main surfaces facing the substrate.

[5] The multilayer ceramic according to claim 2, wherein each of the first and second conductor patterns includes a plurality of strip-shaped conductor portions, whereby the number of turns of the coil-shaped conductor is plural. Manufacturing method of electronic components.

6. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein the core has a flat plate shape, a cylindrical shape, an elliptical column shape, or a donut shape.

[7] The product according to claim 1, wherein the shrinkage suppression layer is disposed so as to form an outermost layer of the composite laminate, and further includes a step of removing the shrinkage suppression layer after the firing step. A method for manufacturing a layered ceramic electronic component.

[8] The shrinkage suppression layer is disposed along a specific interface between the unsintered ceramic layers. In the firing step, the shrinkage suppression layer is a part of the material included in the unsintered ceramic layer. 2. The method for producing a multilayer ceramic electronic component according to claim 1, wherein the multilayered ceramic electronic component is solidified by permeation.

[9] The composite laminated body also has a magnetic ceramic sintered body strength arranged along a specific interface between the unsintered ceramic layers so as to sandwich the core and the coiled conductor in the laminating direction. 2. The method for manufacturing a multilayer ceramic electronic component according to claim 1, further comprising one shield plate.

[10] The composite laminate is a ceramic sintered ceramic that is disposed so as to sandwich the core and the coiled conductor at an interface between the unsintered ceramic layers where the core and the coiled conductor are located. The method for manufacturing a multilayer ceramic electronic component according to claim 9, further comprising a second shield plate having physical strength.

[11] The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein the multilayer ceramic electronic component is a single-function element providing an inductor function.

[12] The green ceramic layer is mainly composed of a low-temperature sintered ceramic material or a magnetic material. 12. The method for producing a multilayer ceramic electronic component according to claim 11, wherein the method is a product.

13. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein the multilayer ceramic electronic component is a multilayer ceramic substrate having a plurality of combined functions including an inductor function.

[14] The method for producing a multilayer ceramic electronic component according to claim 13, wherein the unsintered ceramic layer is mainly composed of a low-temperature sintered ceramic material.

[15] A composite laminate prepared for manufacturing a multilayer ceramic electronic component incorporating an inductor element,

A magnetic ceramic sintered body strength core,

A coiled conductor formed around the core;

At least two unsintered ceramic layers laminated with the core and the coiled conductor sandwiched between layers;

And a shrinkage suppression layer including an inorganic material powder that is disposed in contact with the specific green ceramic layer and that does not substantially sinter at the sintering temperature of the green ceramic layer.

[16] The first and second coiled conductors are respectively formed on the mutually opposing main surfaces of the first and second unsintered ceramic layers sandwiching the core and the coiled conductor. 16. The device according to claim 15, comprising two conductor patterns, wherein the first and second conductor patterns are in contact with each other so as to form a coil-like conductor. Composite laminate.